Exponentially widening mobile phone ownership is opening up the field to new ways of obtaining and disseminating better travel information from and to public transport users, via for example social media and tracking riders' phones. Over 50 US transit agencies, including major actors such as TriMet, in the metropolitan area of Portland, Oregon, Dallas Area Rapid Transit in Texas, and San Francisco's Bay Area Rapid Transit District (BART), as well as smaller operators, now have Facebook and/or Twitter accoun